@Constrosity
Constrosity
Junior Member
I'm giving an old family car a refresh. Luckily got it with only 12,000 miles on it and it's the V6 tbi.

I've put a new tank in it, fuel pump and fuel sender unit, fuel filter, fuel injectors, new battery, and new rims/tires.

It's still not starting. Not even sputtering.

It has spark, as it runs on starting fluid and runs fine. Even sounds good and turns perfectly. I can tell compression is spot on but haven't checked compression. I didn't check with a fuel pressure gauge the psi but I took the fuel lines off from the throttle body and it sprayed and seemed with the stream it has it should be getting enough pressure to the injectors. Also noticed the vent hose from the tank has collapsed and I opened the gas cap to allow pressure to be released on tank.

Will the vent hose not bring connected to the charcoal canister stop the engine from running?

I checked the injector plugs with a noid light and they are pulsing but it seemed the injector pulse might have been weak like running at only 6-7 volts. I checked the new injectors with a 9 volt battery and they open. If this is a sign of what's wrong is there a wire I can re ground it fix to adjust this or is ECM not grounded correctly and how do I fix that?

What I'm wondering is once I re ground the engine to the firewall and engine to the frame and frame to the fire wall. Will this fix the injector pulse being weak? As I'm thinking the voltage is to weak to open them.

Any suggestions everyone? Also pictures or points where the ground wires for ecm and engine are located be appreciated!

Using this as my daily and really need it up and running asap!

Any input appreciated and any one who reads all this your a saint!

Reposted from ( forum electrical)

 

Don’t know anything about monte Carlo’s, but do you have 12v coming from the fuse box to the injector leads ? Or were you measuring voltage by back probing while on the injectors ?

 

This forum is dedicated to ThirdGen F-Body vehicles - Camaro and Firebird. While similar in many basic respects, they are different. The power and ground distribution will be different between the two platforms, so not many of us might have diagrams and details on the G-bodies.

That said, general conventions apply. Connections need to be sound and correct. Adding a ground should never cause any problems, and may help. On an F-Body platform, it's also good to verify clean and tight connections at the ECM, including a reliable ground to its multiple ground connections.

It would be good to verify actual fuel pressure also. I know F-cars with TBI seldom have a test fitting, and I suspect G-bodies are similar. Still, adapting in a fitting to test pressure is worth the effort, even if it only proves that pressure is sufficient. I've fought this before on other platforms, and its amazing how low the fuel pressure can be and still allow a TBI to run, at least a little, sometimes, if it feels like it, maybe.

If it runs on manually added fuel, you've basically proven that the ignition, timing, compression, and mechanicals are basically intact, and not much is left but fuel delivery. In my opinion, it is better to repair the TBI system and avoid any temptation to exchange that for a carburetor, since it will take a lot more than just a carb to ever make it run right.